On 2023-11-17 16:31, Simon wrote:
> As the router supports PD (Prefix Delegation), this means it must be running a DHCPv6 server, and it looks like your client is using this instead of autoconfig.
>
> Can you use something like Wireshark (or it’s command line sibling, tshark) to capture RA packets and decode what flags it is setting for each prefix advertised ?

For the IPv6 setup in my router, it offers these Assigned Types:

ND proxy
SLAAC+Stateless DHCP
DHCPv6
SLAAC+RDNSS

It was set to DHCPv6 for months.

I just changed it to SLAAC+Stateless DHCP, and left the client machine
set to "auto" in /etc/network/interfaces.

It can now get an IPv6 address this way, though it looks very different
from what it received before when it hadh "dhcp" in the interfaces file
and with the Assigned Type set to the prior DHCPv6.

So far dd+nc over IPv6 doesn't stall, even after fifteen minutes of
continuous sending.

I'm not ready to declare it solved - I want to give it a few days.

-Michael